media: saa7164: Fix driver name in debug output

This issue was reported by a user who downloaded a corrupt saa7164
firmware, then went looking for a valid xc5000 firmware to fix the
error displayed...but the device in question has no xc5000, thus after
much effort, the wild goose chase eventually led to a support call.

The xc5000 has nothing to do with saa7164 (as far as I can tell),
so replace the string with saa7164 as well as give a meaningful
hint on the firmware mismatch.

Signed-off-by: Brad Love <brad@nextdimension.cc>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>